Arrhopalites antrobius

Material examined: Lectotype ♀ and 1 paralectotype ♀, 12 ­ iv­ 1965. JAPAN, Yamaguchi, Akiyoshi. Yakujindo cave. Yosii leg., MHN. Caecus­group (Fig. 2, A­K). Body setae as shown in figure D. Antennae of lectotype ~ 2 X as long as the cephalic diagonal. Ant. IV with five ringed subdivisions (Fig. A) apex with a capitate sense rod (Fig. B). Ant. III without basal swelling; sense organ (Fig. C) with 2 parallel sense rods in a single shallow pit; seta Aai club­shaped and blunt; Api slender with a bristle like apex, Ape short and acuminate; Ae, Ap and Ai as a normal elongate setae. 1 + 1 eyes, pigments absent. Dorsal cephalic setae L 1, L 2, IL 2 and IL 3 spinelike, M 3 ­ 5 absent (Fig. J). Metatrochanteral organ (seta D 2) elongate (Fig. G). All ungues with a strong tunica and clear inner tooth (figs. K, a­c). All unguiculi with a strong corner tooth, and apical filament exceeding unguis tip. Corpus tenaculum with two setae (Fig. H). Dens with 7 dorsal E setae, E 1 ­ 5 spinelike; four spinelike L setae present; D 1 ­ 2 and Id 1 ­ 4 present (Fig. E); 5 ventral setae rows (3,2,1,1,1) (Fig. E). Mucro narrow, gutter­like, both edges serrate narrowing at the distal third (Fig. F). Anal valve with 3 + 3 short cuticular spines in the upper flap and 2 + 2 in the ventral flaps; setae C 2 ­ C 8 (but C 7) swollen basally and lamellate, C 7 slender, E 10 ­ 11 absent, chaetotaxy (Fig. I). Female subanal appendage rod­like, somewhat flattened on apical half and apically serrate (Fig. I). Biogeographic zone 3 a. Remarks: This species can be distinguished from other Asian caecus­group species by the number of subsegments of the Ant. IV and the presence of dental L 4 seta.